Asus TUF GAMING H770-PRO WIFI Manual page 16

DO NOT short-circuit the pins except when clearing the RTC RAM. Short-circuiting or
placing a jumper cap will cause system boot failure!
If the steps above do not help, remove the onboard button cell battery and short the two
pins again to clear the CMOS RTC RAM data. After clearing the CMOS, reinstall the button
cell battery.
14. COM Port header
This header is for a serial (COM) port. Connect the serial port module
cable to this header, then install the module to a slot opening at the back
of the system chassis.
The COM port module is purchased separately.
15. Front Panel Audio header
This header is for a chassis-mounted front panel audio I/O module that
supports HD audio standard. Connect one end of the front panel audio I/O
module cable to this header.
We recommend that you connect a high-definition front panel audio
module to this header to avail of the motherboard's high-definition
audio capability.
16. System Panel header
This header supports several chassis-mounted functions.
• System Power LED header (PLED)
The 2-pin and/or 3-1 pin headers allow you to connect the
System Power LED. The System Power LED lights up when
the system is connected to a power source, or when you
turn on the system power, and blinks when the system is in
sleep mode.
• Storage Device Activity LED header (HDD_LED)
The 2-pin header allows you to connect the Storage Device
Activity LED. The Storage Device Activity LED lights up
or blinks when data is read from or written to the storage
device or storage device add-on card.
• System Warning Speaker header (SPEAKER)
The 4-pin header allows you to connect the chassis-mounted system warning speaker.
The speaker allows you to hear system beeps and warnings.
• Power Button/Soft-off Button header (PWRSW)
The 3-1 pin header allows you to connect the system power button. Press the
power button to power up the system, or put the system into sleep or soft-off mode
(depending on the operating system settings).
1-6
COM
PIN 1
AAFP
HD-audio-compliant
pin definition
Chapter 1: Product Introduction